Dozens of exotic animals including tigers, lions and bears were killed by authorities over two days in Ohio after they were freed by their owner before he died of self-inflicted wounds.
Schools were closed and panicked residents were told to stay indoors as the animals roamed free near Zanesville in eastern Ohio.
Authorities killed 49 of the 56 animals, some at close range, including the 18 Bengal tigers, six black bears, two grizzly bears, two wolves and 17 lions, said Muskingum County Sheriff Matt Lutz.
A macaque monkey, possibly carrying the Herpes B virus, remains at large.
One of the escaped big cats reached an interstate highway and was hit by a car. Authorities posted electronic warning signs, "Caution Exotic Animals" for motorists.
"We are not talking about your normal everyday house cat or dog. These are 300-pound Bengal tigers that we had to put down," Sheriff Lutz said. "I gave the order ... that if animals looked like they were on their way out, they were put down."
The dead animals have been buried on the farm, he said. Survivors were taken to the Columbus Zoo, including three leopards, a grizzly and two macaque monkeys.
Owner Terry Thompson (62) who had been charged with animal cruelty 11 times since 2004, was found dead from an apparently self-inflicted wound when authorities went to the farm on Tuesday after reports of animals running free.
They found gates and animal pens open, but no suicide note.
Sheriff Lutz said animals kept at the farm included many types of big cats such as cheetahs, mountain lions and leopards, in addition to lions and tigers.
Authorities said they had received about 35 calls about the menagerie over the years, ranging from animals running loose to animals not being treated properly.
"We've handled numerous complaints here, we've done numerous inspections here," he said. "So this has been a huge problem for us for a number of years."
There were complaints that Mr Thompson left horses undernourished, then fed them to lions when they died, said Larry Hostetler, executive director of the Muskingum County Animal Shelter.
However, he met the bare minimum requirements for keeping the animals, he said. Mr Thompson was released last month from federal prison on a firearms conviction. Sheriff Lutz said Thompson's wife, Marian, was no longer living at the farm. She will return to care for some remaining horses, he said.
Sheriff Lutz said authorities tried to shoot some of the animals with tranquiliser guns but encountered problems.
"We just had a huge tiger, an adult tiger that must've weighed 300 pounds that was very aggressive," he said. "We got a tranquilizer in it and this thing just went crazy."
Barbara Wolfe, a veterinarian, said she shot a tranquilizer dart into the tiger, but it got up and charged her from 4.5 metres away.
A police deputy shot the tiger dead. "I've never been in fear of my life more than then," Ms Wolfe said. She works at The Wilds, a refuge not far away from Zanesville that keeps exotic animals like rhinos and giraffes.
Sheriff Lutz said he issued a shoot-to-kill order on Tuesday evening and stationed officers on Interstate 70 about 1.5 km west of the Zanesville city limits to prevent animals from crossing.
He said he also ordered the schools closed yesterday. "We didn't want kids standing at the bus stop" while wild animals were loose, he said.
Jack Hanna, director emeritus of the Columbus Zoo, told the news conference Sheriff Lutz and his deputies did the right thing.
"These are dangerous animals," Mr Hanna said. "If you had 18 Bengal tigers running around these neighborhoods, you wouldn't have wanted to see what would have happened."